JPH09154205A - Hybrid vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a vehicle which stops its engine in favorable condition according to the running condition and operational situation of the vehicle and starts the engine under required condition. SOLUTION: A vehicle controlling device 101 receives each information signal from an accelerator sensor 102, a vehicle speed sensor 103 and a brake sensor 104. An engine controlling device 105 controls an engine 106 based on a signal from the vehicle controlling device 101 and feeds back the signal of engine speed. A generator controlling device 107 controls the revolutions of a motor for a generator 108 based on a signal from the vehicle controlling device 101 and feeds back each signal of the rotational speed and torque of the motor. A driving motor controlling device 109 controls the operation of a driving motor 110 based on a signal from the vehicle controlling device 101 and also feeds back each signal of the rotational speed and torque of the motor. Electrically connected to the motor for the generator 108 and the driving motor 110, a battery 111 outputs the signal of its condition to the vehicle controlling device 101.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hybrid vehicle having at least an electric motor as a drive source for driving and further including a so-called internal combustion engine.

[0002]

2. Description of the Related Art Conventionally, various types of hybrid type vehicles equipped with an engine and an electric motor are known. However, there are so-called series type hybrid vehicles which use only an electric motor as a driving source of the vehicle. , Are roughly divided into so-called parallel type using an electric motor and an engine as a driving source (see FIG. 7).

In a series type hybrid type vehicle, an electric motor as a traveling drive source is operated by electric power stored in a battery. On the other hand, on the other hand, a rotation generated by driving an engine is transmitted to a generator. Drive
The electric power obtained by this generator is converted into a direct current and sent to a battery for charging (FIG. 7A).

Further, in a parallel type hybrid type vehicle, the vehicle is run by the driving force of both the engine and the electric motor. However, there is a type using both or one of the drive sources depending on the running state and the like. Proposed.

As an example, an engine and an electric motor are connected to a drive shaft of a vehicle through a clutch, and only the electric motor is operated as a drive source at the time of starting, and the clutch is engaged at the time of normal traveling to engage the engine. Drive a hybrid vehicle by driving only
There is a parallel hybrid vehicle that drives both the electric motor and the engine during sudden acceleration (FIG. 7B).

In addition, the engine and the electric motor are connected to each other, and the vehicle is run in an engine drive mode for driving only the engine, a motor drive mode for driving only the electric motor, and an engine / motor drive mode for driving the engine and the electric motor. There is a hybrid vehicle that can A hybrid type in which an engine and a generator are connected as an example of a parallel type, and a part of the output from the engine is transmitted to the generator and the rest is directly transmitted to an output shaft to which an electric motor is connected. There is a vehicle (Fig. 7
C).

Since any hybrid type vehicle is provided with at least an electric motor as a drive source, it is possible to drive the vehicle only with the electric motor. Further, the driving force of the engine may not be required when the vehicle is stopped, decelerated, or travels on a downhill. Even when these engines are not required, the engine continues to be fueled and at least held idle.

Particularly in a hybrid type vehicle, energy may be recovered by a regenerative brake during deceleration. In this case, the inertia energy of the vehicle is stopped by stopping the engine or disconnecting it with a clutch or the like. The energy recovery efficiency is higher when the configuration is such that the energy is transmitted only to.

In any case, when the engine is not used or when the driving force of the engine is not required, in order to suppress wasteful fuel consumption, even if the vehicle is in use, the engine is not used. It has been proposed to shut off the engine by shutting off the fuel supply.

[0010]

When the engine is stopped while the vehicle is in use, it is of course necessary to restart the engine when the driving force of the engine is required thereafter. At the time of starting the engine, wasteful fuel consumption occurs due to the energy required for the rotation of the starter and the operation in the state of poor combustion efficiency at the time of starting.

Further, there are problems such as vibration and rattling noise at the time of starting the engine, and it is disadvantageous to perform many starting operations during traveling. Instead, it was generally held in the idling state.

However, when the engine is not used for a certain time interval, it is preferable to keep the engine stopped. Therefore, a method of stopping the engine by detecting the braking operation of the vehicle has been proposed.
In this case, the depression of the brake pedal is detected to stop the engine, and then the engine is started after the brake is no longer depressed or after a certain period of time elapses.

However, in this case, for example, when traveling downhill on a mountain road or when stopping at a traffic signal or a tollgate on an expressway, a pumping operation of brakes (intermittent stepping for a short time) or Since it will be a long and gentle deceleration,
Along with that, the engine is stopped and started many times.

For this reason, vibrations and noises due to engine start shocks are transmitted from the vehicle to the occupants a number of times, giving passengers an unpleasant feeling and adversely affecting comfort and driving feeling.

Further, as described above, frequent stopping and starting of the engine in a short time may result in poor energy efficiency due to useless fuel consumption at the time of starting in any hybrid type vehicle. The harmful exhaust gas due to poor combustion at this time is also discharged in large amounts according to the starting frequency, and the advantages of the hybrid vehicle are lost.

Further, since the frequency of use of the starter at the time of starting increases, the durability of the starter is required to be higher than that of a general vehicle, which increases the mass of the starter itself and increases the product cost. Becomes

The present invention has been made to solve the above problems, and is a hybrid type vehicle in which the engine is stopped in a preferable state according to the running state and driving state of the vehicle and the engine is started only in a necessary state. The purpose is to provide. Another object of the present invention is to provide a hybrid vehicle that does not start the engine unnecessarily depending on the driving condition of the vehicle. Another object of the present invention is to provide a hybrid type vehicle that eliminates unnecessary engine stop depending on the running condition of the vehicle.

[0018]

In order to achieve the above object, in the invention described in claim 1 of the present application, a hybrid type equipped with an engine and an electric motor and capable of stopping the engine while the vehicle is traveling. A hybrid vehicle, comprising: an engine start control means for starting an engine based on a depression amount and / or a depression time of an accelerator of the vehicle when the engine is stopped.

The present invention can be applied to any of a series type and a parallel type as long as it is a hybrid type vehicle in which at least an electric motor is driven to drive and a so-called internal combustion engine is mounted. In other words, if an electric motor is provided as a drive source, the engine drive force may not be necessary. Therefore, only when it is determined that the engine should be stopped, the engine drive force is stopped. The engine is started when it is necessary.

The engine stop state assumed in the present invention means a state in which at least fuel supply and ignition operation are not performed, the engine rotation itself does not necessarily have to be stopped, and it is in a idling state. Is also good.

Depending on the type of hybrid vehicle, for example, when utilizing a regenerative brake or the like, stopping the engine rotation may increase the regeneration efficiency. Therefore, in these cases, at the same time, the engine rotation is stopped. It is preferable to stop itself. Alternatively, it is possible to disengage the connection with the output shaft from the engine by providing a clutch or the like.

The engine start control means of the present invention performs an engine start operation while the engine is stopped, and operates based on the accelerator depression amount and depression time. Depression amount and depression time of the accelerator, that is,
In other words, the depression information relates to the depression state of the accelerator pedal, and is based on the output information that is detected and output when the accelerator pedal is depressed by the driver's operation.

The operating conditions of the engine start control means include, in addition to the above-described accelerator depression amount (pedal inclination angle) and depression time, whether or not the accelerator (pedal) is depressed and the depression force (pedal). Force) and the like may be adopted. Then, the accelerator detection means capable of detecting these or the accelerator pedal depression state detection means provides information as information, or determines these states from the detection signal.

The engine start control means selects at least one optimum one of the above depression information based on the detection information regarding the depression state of the accelerator, and determines whether to start the engine based on the information. . That is, the engine start determining means is provided for performing a starting operation for starting the engine only when it is determined that the engine should be started based on the accelerator depression amount and the depression time.

The engine starting condition is determined based on the accelerator depression amount / depression time. When the accelerator is depressed, the driving force is increased even when the vehicle is desired to be accelerated or the vehicle is driven at a constant speed on an uphill. Is necessary, the required driving force increases with time. Therefore, it is necessary to judge whether the required driving force is sufficient for the electric motor or whether the engine is required.

In other words, the operating state of the vehicle, which is determined from the accelerator depression state, can be handled by the electric motor alone without starting the engine that consumes the fuel and generates the exhaust gas, or only the electric motor is used. The engine should not be started if there is a situation where it is preferable to deal with. On the contrary, for example, when it is not possible to cope without the driving force of the engine or when it is not possible to cope with it with the electric motor, the engine should be started to utilize the driving force of the engine.

In any case, at least when the driver depresses the accelerator, a driving force larger than the driving force of the vehicle before the depression is required, and the accelerator is depressed when the engine is stopped. If so, as a basis for determining whether to start the engine,
In the present invention, the accelerator depression amount and depression time are selected. In other words, the accelerator depression amount and depression time are selected as conditions for starting the engine,
The engine is supposed to be started based on this.

Therefore, as a general rule, the engine is not started unless the accelerator is depressed, so that unnecessary vibration and noise due to starting, wasteful consumption of fuel, generation of non-combustible gas at starting, etc. are suppressed. .

As the engine starting condition, it is possible to select other information, and for example, the remaining power amount of the power storage means for driving the electric motor can be considered. That is,
When the engine is stopped, only the electric motor is used for driving. However, if the electric power is consumed while the electric motor is being driven and the remaining power cannot keep the electric motor driven, do not wait for the accelerator to be depressed. First, it is preferable to drive the engine.

In this case, the remaining power amount detecting means of the power storage means and the starting determination means based on the remaining power amount detection means are provided. The engine driving force in this case may be used as a driving source for driving the vehicle, as a driving source for a generator that supplies electric power to the power storage unit, or for both. In either case, it is preferable to start the engine and utilize its driving force in order to continuously and stably drive the vehicle.

It is also conceivable to additionally add a time condition from engine stop as an engine start condition. That is, since starting the engine in a short time after stopping the engine leads to frequent start-up operations, the engine is restarted only after a certain time has elapsed after stopping the engine and when the accelerator depression condition is satisfied. Unless the engine is started until the accelerator depression condition is satisfied until a certain period of time elapses, at least engine stop and start are prevented from being repeated continuously in a short time. In this case, the accelerator information detecting means may be provided with a time-lapse means for measuring the passage of time since the engine was stopped and an engine start determining means based thereon.

In the present invention, among the accelerator depression conditions, the depression amount and the time are used as the judgment conditions to determine whether to start the engine individually or in combination. That is, since the engine start control means operates to stop the engine, the hybrid vehicle is in a state suitable for traveling by driving the electric motor. Therefore, it is necessary to start the engine when the driving force of the engine is required to drive only the electric motor, or when it is more suitable to drive the engine than the electric motor.

The case where the engine drive is required in the hybrid type vehicle means that the generator driven by the engine is operated to supply a large amount of electric power when the drive force of the electric motor is insufficient, or the drive force of the engine is not changed. This is the case when the vehicle is used as a driving force, but in particular, the running state of the vehicle when the accelerator is depressed corresponds to these.

While the engine is stopped, it is driven by the electric motor alone, but since it is not used at the limit of the electric motor's independent driving force, the running state before depressing the accelerator is greatly reduced. As long as the traveling state does not change, it is possible to continue the independent traveling with the electric motor.

When the accelerator is depressed, the driver is requesting the driving force from the vehicle. Therefore, in the present invention, the amount of depression of the accelerator is detected and, for example, it is necessary to greatly increase the driving force. In this case, that is, when the accelerator is fully depressed, the engine is started, and when the accelerator is slightly depressed, the engine is not started and only the driving force of the electric motor is maintained. As a result, the driving force of the electric motor can be effectively used to start the engine only when it is necessary, so that unnecessary starting operation can be suppressed.

The criterion for determining the amount of depression of the accelerator (threshold of the amount of depression of the accelerator) is determined by the depression angle of the accelerator pedal, etc., but it is different depending on the vehicle or the configuration of the pedal, so it is appropriate. Just set it.

Further, in the present invention, the depression time of the accelerator can be used as a judgment condition for starting the engine. That is, even if the accelerator is depressed, if the time is extremely short, the driver immediately demands the same driving force as the driving condition before the accelerator is depressed. You can deal with it enough. In such a case, restarting the engine is not appropriate because the energy loss due to the starting operation is large.

Therefore, in the present invention, when the accelerator does not exceed the predetermined time reference value (accelerator time threshold value), the unnecessary starting operation is omitted without starting the engine, and when the reference value is exceeded. Judges that the engine needs to be started, and starts the engine.

Further, according to the present invention, it is possible to determine whether or not to start the engine in a complex manner by taking in both the accelerator depression amount and the time. As an example, if the accelerator depression amount is large and it is extremely short, no further driving force is required at the moment when the accelerator is not depressed. In such a case, it is preferable not to start the engine, because if the engine is started, the engine must be operated thereafter in a situation where the engine is not needed.

On the contrary, if the accelerator depression amount is small and the pedal is depressed for a long time to some extent, the increase amount of the driving force increases with time. In such a case,
Since it is not enough to drive the electric motor alone, it is preferable to start the engine.

As described above, determining whether or not to start the engine based on not only the amount of depression and the time, but also the combined conditions of both, enables stable running without unnecessarily stopping and starting the engine. Can be maintained. These judgments can also be made by the engine start judging means.

Next, in the invention described in claim 2, in the hybrid vehicle according to claim 1, the engine start control means causes the speed of the hybrid vehicle to be higher than a predetermined starting speed threshold value. It is characterized in that the engine is started only in the case.

In the present invention, it is determined whether to start the engine in a complex manner by adding the vehicle speed information in addition to the accelerator depression information to the engine starting condition. Not only for hybrid type vehicles, in order to use the efficient energy of a general internal combustion engine, it is necessary to rotate the engine at a certain speed (usually about 2000 RPM) or higher. However, there are adverse effects such as energy efficiency and exhaust gas resulting from incomplete combustion.

Therefore, when the engine is used in a hybrid type vehicle, it is preferable to use it in a state in which the engine speed rises above a certain level. In other words, when the engine driving force is used, whether it is used as the traveling driving force or the generator driving force, the fuel consumption efficiency peculiar to the engine is excellent when the rotational speed is increased to some extent. Operation in the range of speeds is preferred.

That is, regardless of the type of hybrid vehicle, the engine speed increases when the vehicle speed is high to some extent, but the engine speed often decreases when the vehicle speed is low. In other words, there is less need to use the engine at low speeds, and some use electric motors to compensate for these inefficient parts of the engine.

Therefore, it is preferable not to start the engine unless the vehicle speed exceeds a certain level. On the contrary, when the driving speed of only the electric motor approaches the limit speed, it is preferable to start the engine and utilize the driving force.

In the present invention, the engine is started on the basis of the accelerator pedal depression information on the premise of the vehicle speed, thereby suppressing unnecessary engine starting operations and frequent occurrence of unnecessary fuel consumption. Then, the engine start determining means may be configured to determine whether to start the engine based on such vehicle speed information and accelerator information.

Since the starting speed threshold value is different for each vehicle, there are differences in the type of hybrid vehicle, the driving force of each electric motor and engine, and whether the engine is driven alone or in combination with the electric motor. It may be set as appropriate in consideration. For example, in the low speed range, when the electric motor is driven independently, at least the speed lower than the maximum speed that can be covered by the electric motor becomes the reference value.

According to the invention described in claim 3, claim 1
In the hybrid vehicle according to the item (1), the engine start control means starts the engine only when the remaining power amount of the power storage means for driving the electric motor is less than a predetermined starting power threshold value. .

In the present invention, judgment is made by adding the remaining power information of the power storage means in addition to the accelerator depression information as the engine starting condition. That is, when the engine is stopped, the electric motor is independently driven, but stable running cannot be maintained unless the remaining power of the power storage unit that drives the electric motor is sufficient.

Therefore, even if the accelerator depression condition is, for example, the depression amount or time is equal to or less than the engine start standard, the generator for driving the electric motor is driven, or
Alternatively, it is preferable to use the driving force of the engine as the vehicle driving force. On the other hand, if the amount of remaining power is sufficient, it is not necessary to start the engine in order to effectively utilize the driving force of the electric motor and prevent the problems associated with starting the engine.

For this reason, according to the present invention, the engine is started based on the accelerator depression information when the remaining power amount of the power storage means is equal to or less than the reference value (starting power threshold value). Since the starting power threshold differs for each vehicle, consider the type of hybrid vehicle, the driving force of individual electric motors and engines, and the difference between single drive of the engine and combined drive with the electric motor. It may be set appropriately.

For example, when the electric motor is driven independently in the low speed range, the amount of accumulated electric power sufficient for at least the driving force of the electric motor becomes the reference value. Although it depends on the accelerator pedal depression information, the required driving force differs depending on whether the depression amount is large or small, so the range that the electric motor can cover with the remaining power also differs. The threshold value of the remaining power serving as a reference may be set appropriately.

It should be noted that the power storage means referred to here is sufficient as long as it is for driving an electric motor, and is not limited to a battery utilizing chemical change, and for example, a capacitor, a flywheel battery, a hydraulic accumulator, a pneumatic accumulator. And so on.

Next, the invention described in claim 4 is a hybrid type vehicle comprising an engine and an electric motor, capable of stopping the engine while the vehicle is traveling,
A hybrid vehicle characterized by comprising engine stop control means for stopping the engine based on the amount of depression and / or the depression time of the brake of the vehicle when the engine is operating.

The operation of the engine assumed in the present invention means a state in which fuel supply and ignition operation are being performed on the engine, and generally means a state in which the engine rotates by self-sustaining operation.

The engine stop control means of the present invention performs an engine stop operation while the engine is operating, and operates based on the amount and time of depression of the brake by the driver. Brake depression amount and depression time,
That is, the depression information, in other words, relates to the depression state of the brake pedal, and is based on the output information that is detected and output when the brake pedal is depressed by the operation of the driver.

The operating conditions of the engine stop control means include, in addition to the above-mentioned amount of depression of the brake (inclination angle of the pedal) and depression time, whether or not the brake (pedal) is depressed (the brake is activated). Whether or not the pedal is depressed), the depression force (force applied to the pedal), or the like may be used. And a brake detection means capable of detecting these,
Alternatively, it is determined whether the information is sent from the brake pedal depression state detecting means or based on these detection signals.

As an example, it is conceivable to stop the engine when the state where the brake pedal is depressed is detected (when the depression is started). In this case, the engine is stopped at the same time as deceleration, so only the electric motor is driven. However, when regenerative braking is taken into consideration, energy recovery by regenerative braking is most efficiently recovered.

In this way, the engine stop control means selects the optimum one from the above-mentioned depression information based on the detection information relating to the depression state of the brake, and determines whether or not to stop the engine based on that information. To do. That is, the engine stop determination means is provided to perform a stop operation to stop the engine only when it is determined that the engine should be stopped based on the amount of depression and the time of depression of the brake.

The judgment based on the brake depression information is whether the vehicle is decelerated or stopped when the brake is operated. In this state, no further driving force is required.

In other words, even if the engine that consumes the fuel and generates the exhaust gas is stopped, the operating state of the vehicle will not be adversely affected. Therefore, if wasteful consumption of fuel and suppression of generation of exhaust gas are taken into consideration. , The engine should be stopped. Therefore, in the present invention, the brake depression information is selected as the condition for stopping the engine, and the engine is stopped based on this information.

As a result, the engine is stopped when the engine is not needed, and the stopped state is maintained unless the accelerator is depressed by the engine start control means, so that wasteful fuel consumption and exhaust gas generation are suppressed. It has become possible.

According to the present invention, one or both of the information on the amount of depression of the brake (pedal) and the information on the depression time is used from the above-mentioned information on the depression of the brake as a judgment material for stopping the engine.

The amount of depression of the brake is, in other words, the amount (or angle) of depression of the brake pedal. However, in a general driving state, the amount of depression is large when the vehicle is going to be stopped, and temporary deceleration is caused. Sometimes the amount of depression is small. Further, the brake pedal has a slight angular allowance (so-called play) until the brake actually operates.

In this play range, the brake is not actually operated, and in general, there is a state in which the driver lightly puts his / her foot on the brake in the front safety confirmation state. Then, if the brake is really required, the driver further depresses the pedal, and in this case, when the vehicle is to be significantly decelerated or stopped, the brake is largely depressed. On the contrary, if the vehicle is slightly decelerating, depress the brake lightly (smallly).

It is the former that needs to stop the engine, and in the latter case, since the vehicle runs at a constant speed or accelerates after confirmation of safety, the running state before the brake is applied, that is, the operating state of the engine. Is preferably maintained.

Therefore, according to the present invention, it is judged whether or not the brake pedal has been depressed to a predetermined range including the play range of the brake pedal. If the brake pedal is small, the engine is not stopped and the brake pedal is depressed. The engine is supposed to be stopped only when it is large.

The amount of depression (threshold of the amount of depression of the brake), which is the criterion for this judgment, differs depending on the vehicle and the configuration of the brake pedal, and may be appropriately selected from the test results, the member configuration, and the like.

Next, in the present invention, the engine is stopped with the depression time of the brake as the target for determining the engine stop.
That is, the time length of depression of the brake depression information is also related to the length of time required for braking. For example, when the vehicle is temporarily decelerated during traveling, the brake is depressed only for a short time, but when it is desired to stop the brake, the brake is continuously depressed for a certain length of time.
Further, for example, even when the brake is momentarily depressed, stopping the engine one by one causes frequent start operations.

For this reason, it is often preferable not to stop the engine when the brake depression time is short, and it is preferable to stop the engine when the brake is depressed for a certain length.

Further, the depression time referred to here is preferably the time when the brake pedal is actually depressed in consideration of the play of the brake pedal as described above. This is because it is unlikely that the engine will need to be stopped if the brakes are applied.

The engine is stopped when the depression time exceeds a predetermined judgment reference time (threshold of the brake depression time), and is not stopped when the depression time does not exceed the predetermined judgment reference time.

Further, in the present invention, both the amount of depression of the brake and the time can be adopted as the conditions for judging the engine stop. As an example, when the vehicle is traveling at a constant speed, even when it is stopped, the brake may be lightly pressed, and the amount of depression may not reach the reference for stopping the engine (threshold of the amount of depression). Even in this case, if you have the intention to stop, you will continue to brake, so
The driving force of the engine is not necessary, and it is preferable to stop the engine.

On the contrary, when the speed is greatly reduced in a traveling state at a certain speed, the brake may be stepped on a lot, but the stepping time is short. In such a case, since the traveling state is maintained after the vehicle is decelerated, it is often necessary to drive the engine, and it is preferable not to stop the engine.

Therefore, it is possible to determine whether to stop the engine based on not only the amount of depression and the time but also the combined conditions of both, and to perform stable running without unnecessary stop and start of the engine. Can be maintained.

Even if the threshold value used as the criterion for judgment is the same as the case of making the judgment independently and the case of making the judgment in combination (the above-mentioned first threshold value of the brake depression amount and the first threshold value of the brake depression period). , Even if they are different (second brake depression amount threshold value and second brake depression time threshold value)
Alternatively, different values may be used depending on the driving situation. Then, these judgments are made by the engine stop judging means.

Next, in the invention described in claim 5, in the hybrid vehicle according to claim 4, the engine stop control means causes the speed of the hybrid vehicle to be smaller than a predetermined stop speed threshold value. The feature is that the engine is stopped only in the case.

In the present invention, in addition to the brake depression information, the hybrid vehicle speed information is used in combination as a condition for determining whether to stop the engine. That is, when the speed is lower than the predetermined stop speed threshold (the speed is slow), the engine is stopped based on the brake depression information, but when the speed is higher than the stop speed threshold (the speed is fast), Do not stop the engine regardless of the brake depression information.

In a hybrid type vehicle, the engine is normally operating when traveling at a speed higher than a certain level. For example, in the series type that uses only an electric motor as a drive source, the electric power consumption of the electric motor is large during high-speed traveling to some extent, so the engine is operated in order to operate the generator and continuously supply electric power. There is.

Even in the parallel type in which the engine and the electric motor are used together, the engine is better in energy efficiency during high-speed running to some extent, and the driving force of the electric motor alone is not sufficient. It is driven in combination with an electric motor.

Therefore, when the vehicle is traveling at a high speed to some extent, for example, when the vehicle is decelerated to maintain a certain speed, the engine is driven immediately even if the engine is stopped by depressing the brake. May be required (series type or parallel type combined drive), or stopping the engine itself may hinder stable running (parallel type engine independent drive).

On the other hand, when the vehicle is running at a low speed to some extent, the energy efficiency of the engine is poor, the electric power consumption of the electric motor is small, and the electric motor driving force is sufficient to drive the vehicle. Can reduce waste of energy. For example, when the vehicle is to be stopped, the brake is operated to stop the vehicle from a low speed running state, but in this case, it is preferable to stop the engine for efficient energy recovery of regenerative braking.

Therefore, in the present invention, the engine is stopped on the basis of the information on the depression of the brake on the premise of the speed of the vehicle, thereby suppressing unnecessary engine stop operation and frequent start operation. The judgment as to whether or not to stop these is made by the engine stop judging means by adding the speed information together with the brake information.

Since the stop speed threshold value differs for each vehicle, there are also differences in the hybrid vehicle type, individual electric motor and engine driving force, and whether the engine is driven alone or in combination with the electric motor. It may be set as appropriate in consideration.

For example, in the low speed region, when the electric motor is driven independently, at least the speed higher than the maximum speed that can be covered by the electric motor becomes the reference value. vice versa,
In the high speed range, when the engine is driven by the engine alone, the speed lower than the minimum speed of the engine driven alone becomes the reference value.

Next, in the invention described in claim 6, in the hybrid vehicle according to claim 4, the engine stop control means is configured such that the remaining power amount of the power storage means for driving the electric motor is preset. The engine is stopped only when the value is greater than the predetermined stop power threshold value.

In the present invention, the engine stop condition is determined by adding the remaining power information of the power storage means in addition to the brake depression information. That is, stopping the engine is a single drive of the electric motor driven by the power storage means, so that it is premised that sufficient power is stored in the power storage means in order to use the electric motor efficiently. Becomes Therefore, it is not preferable to stop the engine when the amount of remaining power of the power storage unit is not sufficient.

In other words, if the remaining amount of electricity in the power storage means is insufficient, the driving force of the electric motor will not be secured sufficiently, and if the engine is stopped, the driving force of the vehicle will not be secured sufficiently, or The power supply from the generator driven by the engine is stopped, and the driving force of the electric motor is not sufficiently guaranteed.

The amount of remaining power of the power storage means is based on whether or not sufficient power has been accumulated for the driving force of the electric motor. For example, whether or not the required driving force power can be obtained or is usually necessary. The reference value of the remaining power amount, that is, the first power threshold value is determined depending on whether or not the operation for the continued time can be maintained.

In the present invention, the engine is stopped based on the brake depression information when the remaining power amount of the power storage means is larger than the stop power threshold value, but when the remaining power amount is smaller than the stop power threshold value, the engine is stopped. Is not preferable for stable driving, so the engine is not stopped. Then, these judgments can also be made by the engine stop judging means.

The electric storage means referred to here is only required to drive the electric motor, and is not limited to the battery utilizing chemical change, and may be, for example, a capacitor, a flywheel battery, a hydraulic accumulator, a pneumatic accumulator. And so on.

Next, the invention described in claim 7 relates to a hybrid type vehicle based on the optimum embodiment of the present invention. The present invention relates to a hybrid type vehicle that includes an engine as a traveling drive source and an electric motor, and that can stop the engine while the vehicle is traveling, and a brake detection unit that detects a stepping amount of a brake of the vehicle, and a vehicle Accelerator detection means for detecting the accelerator pedal depression state, engine detection means for detecting whether the engine is operating, vehicle speed detection means for detecting the speed of the vehicle, and electricity storage means for driving the electric motor And a power storage detecting unit that detects the remaining power amount of

Further, according to the present invention, when the engine detecting means detects that the engine is stopped, the starting speed determined based on the remaining power amount of the power storing means detected by the power storing means. Engine start determination means for comparing the threshold value and the brake depression amount start condition with the vehicle speed detected by the vehicle speed detection means and the brake depression amount detected by the brake detection means to determine whether or not to start the engine. And engine starting means for starting the engine when the engine start determining means determines that the engine should be started.

In addition, according to the present invention, when the engine detection means detects that the engine is operating, the stop determined based on the remaining power amount of the power storage means detected by the power storage detection means. An engine that determines whether to stop the engine by comparing a speed threshold value and a brake depression amount stop condition with a vehicle speed detected by the vehicle speed detection unit and a brake depression amount detected by the brake detection unit. Stop determination means,
And an engine stopping means for stopping the engine when the engine stop determining means determines that the engine should be stopped.

In the engine stop control means according to the present invention, whether the engine is stopped or not is determined by the engine stop determination means as the engine stop determination means, and the amount of brake depression and the duration of depression, the vehicle speed, and the amount of remaining power of the power storage means are determined. Make a comprehensive judgment and make a decision.

An example of stopping the engine in the present invention is when the amount of depression of the brake is large, the depression time is long, the vehicle speed is slow, and the amount of remaining power of the power storage means is sufficient. On the contrary, when the detection signal is received from the storage means remaining amount detecting means when the remaining amount of the storage means is smaller than a predetermined value, the engine stop control means is irrespective of whether the brake depression or the vehicle speed detection signal is received. Does not stop the engine.

As a result, the drive of the electric motor is complemented by the engine, and when the generator operates the engine, the storage means is also charged, so that the storage means is prevented from being over-discharged.

Further, in the engine start control means of the present invention, whether or not the engine is started by the engine start determination means as the engine start determination means depends on the accelerator depression amount and depression time, the vehicle speed, and the remaining power of the storage means. Determine the amount comprehensively.

An example of the case of starting the engine in the present invention is when the amount of depression of the brake is large, the depression time is long, the vehicle speed is fast, and the amount of remaining power of the power storage means is not sufficient.

On the contrary, when the remaining amount of the electricity storage means detected by the electricity storage means remaining amount detection means is larger than a predetermined value, and the vehicle speed is running at a low speed equal to or lower than the speed reference value (for example, when the vehicle is stopped). ), The engine is not started until a predetermined speed is reached or the remaining power amount of the power storage unit becomes equal to or less than the reference value regardless of the accelerator depression amount and time. This suppresses unnecessary engine starting operations.

The power storage means referred to here is only required to drive the electric motor, and is not limited to the battery utilizing the chemical change. For example, a capacitor, a flywheel battery, a hydraulic accumulator, a pneumatic accumulator. And so on.

[0103]

Next, an embodiment of the present invention will be described. First, FIG. 7 shows a schematic configuration of a hybrid vehicle.
Shown in FIG. 7A shows a schematic structure of a so-called series type hybrid vehicle.
The electric power for driving is supplied from the battery 709 to the electric motor 703 as a vehicle drive source that is connected to the drive wheel through the electric motor 1. Further, a generator 70 driven by the engine 707
5 is provided and electric power is supplied to the battery 709, and an engine for driving the vehicle is not provided.

FIG. 7B shows an example of a parallel type hybrid vehicle in which an engine and an electric motor are used together as a vehicle drive source. An engine 717 and an electric motor 716 are arranged in series in a vehicle drive system. Has been done. The output shaft of the electric motor 716 driven by the battery 719 is
It is connected to the drive wheels via a differential 711. further,
The engine 717 is also connected to the vehicle drive system via the clutch 718. The electric motor 716 also serves as a generator, and supplies regenerative electric power to the battery 719 when the engine is independently driven or during regenerative braking.

In this type, the clutch 718 is engaged when the vehicle drive force from the engine 717 is required, and the vehicle is a vehicle drive source together with the electric motor 716 or the engine 717 alone.

FIG. 7C is a parallel type modification type in which the output shaft from the engine 737 and the output shaft of the motor 733 are connected in parallel to the vehicle drive shaft, and each of them is independent. Alternatively, the vehicle driving force is transmitted together.

A drive shaft gear 741 is connected to the diff 731 connected to the drive wheels, and an electric motor output gear 743 and an engine output gear 747 are connected. The engine output gear 747 constitutes a planetary (differential) gear unit together with a planetary gear 748 connected to the output shaft of the engine 737 and a sun gear 745 connected to the drive shaft of the generator 735.

By providing the planetary gear unit, the engine and the electric motor can be switched or used together without using a clutch. It is preferable to include a generator brake 751 that fixes the drive shaft of the generator 735 for the operation of the planetary gears. This is because the engine output is efficiently transmitted to the vehicle drive system via the planetary gears.

The generator 735 is operated mainly by the driving force of the engine 737 via the planetary gear unit, and supplies electric power to the electric motor driving battery 739. Also, during regenerative braking, the engine rotation is stopped (or the output shaft of the engine is disengaged and fixed with a clutch etc. to stop the rotation), and the regenerative braking force is also supplied to the generator. Collection is also possible.

However, in the case of a general hybrid vehicle, it is more common to supply most of the regenerative braking force to the electric motor by inertial rotation with the fuel supply and ignition operation stopped, and to recover energy from the electric motor. Good collection efficiency.

In any case, since the driving force of the engine is not required especially during regenerative braking, it is preferable to stop the engine (at least stop the fuel supply) in order to suppress unnecessary fuel consumption during that time.

Further, in any type of hybrid vehicle, the electric motor is connected to the vehicle drive system, so that the engine can be stopped during the required use (operation). This is because the driving force while the engine is stopped is supplied from the electric motor.

Next, the schematic structure of the control system of the hybrid vehicle according to the first embodiment of the present invention will be described with reference to the block diagram shown in FIG. In the following description, the example in which the present invention is applied to the hybrid vehicle shown in FIG. 7C is used, but the invention can be applied to other types of hybrid vehicles.

The vehicle control means 101 constitutes the overall control system of the hybrid vehicle according to the present invention, and includes a part or all of each control means in the present invention. The following information signals are input to the vehicle control device 101, and the operation of the engine, the electric motor, and the generator is controlled based on each information signal.

First, the accelerator sensor 102 as an accelerator detecting means for detecting the depression state of the accelerator pedal.
From, an information signal of the accelerator opening α based on the amount of depression of the accelerator (pedal) is input. Further, an information signal of the vehicle speed V is input from a vehicle speed sensor 103 as a speed detecting means for detecting the speed of the hybrid vehicle. In addition, an information signal of the brake depression amount β is input from the brake sensor 104 as a brake detection unit that detects the depression state of the brake pedal.

For example, when the vehicle speed V is equal to or lower than the speed reference value, the engine is stopped to switch to the independent drive of only the electric motor, or when the brake is depressed, regenerative braking is performed. A control signal for stopping the engine is output to each control device.

The engine control unit 105 controls the engine 10
6 controls the fuel supply state to 6, the ignition operation, and the like. Here, based on the throttle signal including the ON / OFF information from the vehicle control means 101, the throttle opening information θ is output to the engine (the throttle actuator thereof, not shown) to adjust the fuel supply to the engine. To do. further,
An information signal of the actual engine speed Ne is fed back from the engine 106 to the vehicle control device 101.

Therefore, the engine control device 105 constitutes the engine stop control means and engine start means of the present invention together with the vehicle control means 101. That is, when the vehicle control means 101 as the engine stop determination means determines that the engine should be stopped, a throttle OFF signal is input to the engine control device 105, and based on this, the throttle opening to stop the fuel supply is performed. A control signal that makes the degree θ zero is output, and the ignition operation of the engine is stopped. On the contrary, when the vehicle control means 101 as the engine start determination determines that the engine should be started, a throttle ON signal is output to the engine control device 105, and a control signal to the start means including the starter of the engine. Is output.

The generator control device 107 is the vehicle control device 1.
01 based on the control signal from the generator motor 108
Is driven by the driving force of the engine or the regenerative braking force to supply electric power to the battery 111. And sometimes,
A driving current is supplied to the generator 108 to drive the generator as an electric motor (generator motor). Alternatively, the idling state is set, or, for example, the generator brake 751 in FIG. 7C is used.
There is also a case where it is activated to bring it into a fixed state.

These are controlled in order to select and operate each gear element of the differential gear unit in this embodiment on a timely basis based on the rotation speed of the drive shaft (gear 741) of the vehicle judged from the vehicle speed information. To be done. For example, the rotational speed of the gear 747 as a third gear element of the planetary gear unit is calculated from the rotational speed of the gear 741 (calculated from the ratio of the number of teeth Z ₃ and Z _5). Further, the gear 74 as the first gear element
5, the rotation speed of the gear 745 (generator) can be calculated from the gear 748 as the second gear element, the number of teeth (Z ₆ , Z ₇ , and Z ₈ ) of these and the relative positional relationship.

Then, the generator control device 107 operates as a generator according to the driving state of the engine or the regenerative state of the vehicle, or is fixed so as to transmit the engine output to the vehicle drive shaft without waste, or In some cases, it is driven as a generator / motor in order to prevent changes in the engine speed and driving force (torque) from being transmitted to the vehicle drive shaft via the differential gears when the vehicle is started or stopped.

The drive motor control device 109 outputs a drive power (torque) signal to the drive motor 110 as an electric motor based on the drive control signal from the vehicle control device 101 to control the operation of the drive motor 110. To do. Further, each signal of the rotation speed Nm of the drive motor and the output torque Tm is fed back.

The vehicle control device 101 controls the accelerator opening α,
Based on information such as the vehicle speed V and the brake pedal depression amount β,
The output torque of the drive motor is calculated and the drive torque Tm *
Output a control signal.

The generator motor 108 and the drive motor 110 are both electrically connected to the battery 111 so that they can be charged and discharged. The battery 111 is provided with a battery state (remaining power amount) detecting means (not shown), and a signal of the remaining power amount is output to the vehicle control device 101. Then, the vehicle control device 101 determines whether or not the engine should be stopped based on the remaining power information of the battery.

In this embodiment, the battery 111 is used as a power supply device (power storage means) for exchanging electric power between the generator 108 and the drive motor 110, but other types of power supplies may be used. For example, capacitors, flywheel batteries, hydraulic accumulators, pneumatic accumulators and the like.

As the capacitor, for example, an electric double layer capacitor having a large capacity per unit volume, a low resistance and a large output density, and other capacitors are used. At this time, the voltage value of the capacitor is used as the remaining power SOC.

The flywheel battery is a motor arranged coaxially with the flywheel, and is a battery for exchanging electric power by driving and regenerating the flywheel. The number of revolutions of the flywheel is used as the remaining power SOC at this time.

The hydraulic accumulator and the pneumatic accumulator are batteries that transfer electric power by taking in and out hydraulic and pneumatic pressures connected to the accumulator. Hydraulic pressure / pneumatic pressure is used as the remaining power SOC at this time.

Next, the engine stop and start control operation in the first embodiment of the present invention will be described with reference to the flowchart of FIG. Here, an example in which the present invention is applied to the hybrid vehicle shown in FIG. 7C will be described, but it goes without saying that the invention can also be applied to other hybrid vehicles.

In the present embodiment, the engine stop control means uses the brake depression information and the vehicle speed information as the judgment material. Further, the engine start control means uses the accelerator depression information and the vehicle speed information as the judgment conditions.

As shown in FIG. 1, this hybrid type vehicle is provided with a brake depression state detecting means, an accelerator depression state detecting means, and a vehicle speed detecting means, each of which has a brake depression information signal, An accelerator depression information signal and a vehicle speed information signal are input to the control means.

First, the engine stop operation by the engine stop control means will be described. When the brake pedal is depressed while the hybrid vehicle is running, brake depression information is input to the control means (step 201). Upon receipt of this brake depression information, the vehicle control means determines whether or not the engine is in operation (step 20).
2). Here, "during operation" refers to a state in which fuel is supplied to the engine and the ignition device is operating, and does not include a state in which the engine is idling.

When the engine is running, the flow of control proceeds to step 203 to determine whether or not the engine should be stopped. When the engine is not in operation, the routine proceeds to step 206, where it is determined whether or not the engine should be started. Since the starting condition is determined by receiving the accelerator depression information by the engine starting means, unless the accelerator is depressed again, the engine is depressed. Ends without starting.

At step 203, it is judged from the brake depression amount and the vehicle speed whether or not the engine stop condition is satisfied. That is, the information on the amount of depression is selected from the information on the depression of the brake, and the vehicle speed information from the vehicle speed detecting means at the time of this input is also input. Step 20
At 4, it is determined whether the engine should be stopped based on the engine stop condition obtained at step 203.
When the engine should be stopped, the routine proceeds to step 205, where the engine stop processing is performed to end the engine stop control operation. When it is determined that the engine should not be stopped, the control operation is ended and the operating state of the engine is maintained.

By the way, the determination as to whether or not the engine should be stopped based on these information may be appropriately determined according to the characteristics of the vehicle, and an example thereof is shown in FIG. The vertical axis is the brake depression amount (%), and the horizontal axis is the vehicle speed (km /
h). The brake depression amount is based on the movable range of the brake pedal, and the maximum movable range is 100%, which includes play. Therefore, to give an example, as shown in FIG. 8, it is the regenerative braking from 2% and the mechanical braking from 20% that actually starts the braking.

Here, the engine stop conditions when the engine is operating are defined as follows. The brake depression amount threshold is a threshold for stopping the engine, and the stop condition β _off is that the brake depression amount is 12%.
In this case, on the other hand, the stop condition β _on as a threshold value for not stopping the engine adopts two threshold values when the depression amount is 2%.

The threshold value of 12% is adopted because when the brake pedal is depressed to this extent, the brake pedal is reliably depressed and a considerable amount of regenerative braking acts, so that the allowable charge of the battery is reduced. Because it is close to electricity. In addition, the reason why 2% is adopted as the threshold value is to consider the amount of play of the brake pedal.
This is because it is possible to accelerate immediately even if only the foot is put on the brake pedal, or it is only within the error range of the brake depression amount detecting means.

Furthermore, the engine is used as the reference value of the speed.
First speed threshold V for stopping _off1As 5km /
h, a second speed threshold V for not stopping the engine
_off245 km / h is adopted.

5 Km / h and 45 Km / h as threshold values
The above two types are provided to prevent frequent judgments. Also, the former is adopted because at this speed, it can be seen that it is almost the same as the stopped state. Therefore, 0 instead of 5 km / h
(Zero) Km / h may be adopted.

On the other hand, the reason why the latter is adopted is as follows. That is, when the engine is stopped when the vehicle speed is 45 km / h, the generator rotation speed is 600 which is the maximum rotation speed.
This is because the speed becomes 5600 rpm, which is close to 0 rpm, which causes a problem that the generator is destroyed, and when the engine is started by the generator, there is a problem that the torque is insufficient and the engine cannot be started. Therefore, other values may be adopted in consideration of the characteristics of the generator.

As described above, the speed is 4 when the present embodiment is summarized.
When traveling at 5 km / h or more, the engine does not stop even if the brake pedal is depressed, and when traveling at 5 km / h or less, regardless of the amount of depression of the brake pedal, as long as the brake pedal is depressed. The engine stops. On the other hand, when the vehicle speed is 5 to 45 km / h, it is determined whether or not the engine is stopped depending on the amount of brake depression. When the vehicle speed is 2% or less, the engine does not stop, and 12% or more is depressed. In some cases the engine will stop.

Next, the operation of the first embodiment relating to the engine start control means will be described with reference to FIGS.
When the accelerator pedal is depressed while the hybrid vehicle is in operation, accelerator depression information is input to the control means (step 201), and the control means determines whether the engine is in operation (step 202).

When the engine is running, the flow of control proceeds to step 203 to judge whether or not the engine should be stopped. However, the engine is not stopped unless the accelerator and the brake are simultaneously depressed, so the engine is stopped as it is. Without doing so, the control operation is ended.

When the engine is not in operation (when it is in a stopped state), the routine proceeds to step 206, where it is judged whether or not the engine should be started. Here, in addition to brake depression information, speed information at that time is also taken in at the same time. Then, based on the brake depression information and the vehicle speed information, it is determined whether or not to start the engine based on the engine start control map (FIG. 3) as described above.

Here, although the brake is not normally depressed when the accelerator is depressed, if the same control map is used as one aspect of engine stop / start conditions, the accelerator is not depressed. The state is on the horizontal axis.

Here, in the engine starting control means, the starting speed threshold value V _on for starting the engine when the engine is stopped is set to 8 km / h. Therefore, 8 km / h
If the speed is less than, it will not start even if you step on the accelerator,
The engine starts when the accelerator is stepped on at 8 km / h or more.

The V _{on is set} to 8 Km / h because it is 8 Km / h in the hybrid type vehicle assumed in this embodiment.
This is because in the state of less than h, the speed range is such that sufficient driving force can be obtained even when the vehicle is driven only by the electric motor. In addition, in order to use the engine for driving the vehicle in this speed range, the engine speed must be low or the gear ratio must be reduced to increase the engine speed. Is bad.

That is, in this embodiment, as shown in FIG. 9, the engine practical lower limit rotation speed, which is the lower limit of the rotation speed at which torque is generated without vibration when the throttle is opened, is about 1800 rpm. . At this level of rotation speed, unless the vehicle speed is 7.74 Km / h or more, the engine is idling even when it is started, and the situation in which it cannot be practically used occurs. 8 km / h is adopted as _on . Therefore, V _on may be set to another value in consideration of vehicle characteristics and the like.

Then, in step 207, processing for obtaining the engine starting condition from the brake depression condition and the vehicle speed is performed. However, since the brakes are not often depressed at the same time, if the vehicle speed is less than 8 km / h, When it is judged that the engine should not be started, the control operation is ended without starting the engine.

In step 207, the vehicle speed is 8 km.
If it is greater than or equal to / h, the process proceeds to step 208 and the accelerator depression information is examined. Since only the accelerator depression information is determined here, it is determined that the engine should be started, and the process proceeds to step 209 to perform the engine start processing,
Control ends.

Further, regarding the accelerator information, here, the case is shown in which only the information as to whether or not the accelerator is depressed is used depending on the speed, but it may be configured to depend on the accelerator depression amount. In another embodiment of the present invention, it is determined whether or not the engine should be started based on the accelerator depression amount. In that case,
In consideration of sensor input error and the like, a value of about 2% may be adopted as the accelerator depression amount.

On the other hand, in the embodiment of the present invention, the control operation when the brake and the accelerator are both depressed at the same time is also shown. That is, when the vehicle speed exceeds 8 km / h, the control to start the engine is performed if the brake depression amount is less than 2%, but the engine is not started if the brake depression amount exceeds 2%. It has become a thing.

That is, in step 206, when the accelerator and brake depression information detected in step 201 are detected at the same time, it is determined whether or not the brake depression amount is larger than 2% based on the control map described above. If it is larger, it is determined in step 207 that the engine should not be started, and the control operation is ended without starting the engine.

On the contrary, when the amount of depression of the brake is less than 2%, it is determined in step 207 that the engine may be started, and the process proceeds to step 209 to determine whether to start the engine based on the accelerator depression information. To judge.

As described above, even if the accelerator and the brake are erroneously stepped on at the same time, it is determined whether or not the engine should be started based on the stepped state of the brake. Therefore, malfunction is prevented and safety is improved. There is.

In any control, the control is returned after the control is completed. Therefore, for example, when the brake pedal is depressed while the engine is operating, the engine is not stopped because the speed is faster than the engine stop condition, and even if the control is terminated, the speed is reduced while repeating this determination, The engine is stopped in the state where the engine is decelerated to a speed equal to or lower than the speed reference.

When the engine is started, for example, when the accelerator is continuously depressed from the stopped state, the control ends without starting the engine until the speed reference is reached, but the speed is reduced by driving the electric motor. When the standard value is exceeded, the engine is started.

As described above, according to the first embodiment of the present invention, unnecessary stop and start of the engine are not performed while the hybrid vehicle is in operation, so that vibrations and fuel consumption due to frequent start operations are generated. Waste can be suppressed.

Next, a second embodiment of the present invention will be described with reference to FIG. Similar to the first embodiment described above, the present invention is applied to a hybrid type vehicle, but is also applicable to other hybrid type vehicles.

In this embodiment, the engine stop control means uses the brake depression information and the vehicle speed information as the judgment material. Further, the engine start control means uses the accelerator depression information (time) and the vehicle speed information as the judgment conditions. Further, a brake depression state detecting means, an accelerator depression state detecting means, and a vehicle speed detecting means as shown in FIG. 1 are provided, each of which is a brake depression information signal, an accelerator depression information signal, and a vehicle speed information signal. Is input to the control means.

FIG. 4 is a flow chart showing the control operation in the second embodiment of the present invention, in which the judgment condition is the continuous depression time of the accelerator (pedal) in the accelerator depression information in the engine start control. The present embodiment is different from the previous embodiment in the points, but the other points are almost the same.

In this engine start control means, the continuous depression time of the accelerator is counted by the counter provided in the control loop. Specifically, steps 411 and 412 are used as a counter for the accelerator depression time.
Is provided, and accordingly, steps 405 and 410 for resetting the counter are newly provided.

In this embodiment, the control operation of the engine stop control means is almost the same as that of the first embodiment, so that it will be briefly described. First, when the brake depression information is input (step 401), it is determined whether the engine is in operation (step 402). If the engine is not in operation, the process proceeds to step 407, and the accelerator is normally depressed. Since the brake is depressed without it,
The control operation ends as it is.

If the engine is in operation at step 402, the routine proceeds to step 403, where the vehicle speed at this point and the depression amount of the depression information of the brake are taken in, and the control map shown in FIG. According to, determine whether to stop the engine.

If the engine stop condition is not satisfied, the control operation is terminated without stopping the engine (step 404). On the contrary, when the engine stop condition is satisfied, the engine is stopped, but at that time, the elapsed time counter of the accelerator depression time is reset (Ca _on = 0).

Next, the operation of the engine start control means in this embodiment will be described. When the accelerator depression information is input to the control means (step 401), it is determined whether or not the engine is in operation (step 402). If the engine is in operation, after proceeding to step 403, the normal operation is performed. Brakes are not depressed at the same time, so
The control operation is ended without stopping the engine while maintaining the operating condition.

When the engine is stopped at step 402, the routine proceeds to step 407, where it is judged from the brake depression information and the vehicle speed information whether or not the engine can be started according to the map of FIG.

As described above, when the amount of depression of the brake is 2% or more, and when the vehicle speed is less than 8 km / h, it is assumed that the engine should not be started and the control operation is terminated without starting the engine. Yes (Step 40
8). At this time, the accelerator depression time counter is reset (step 410).

If it is determined in step 408 that the engine should be started (the vehicle speed is 8 km / h or more and the brake is not depressed or the depression amount is less than 2%), the accelerator information is used. It is determined whether to start the engine (step 409).

Here, as in the above-described embodiment, the accelerator is depressed (the accelerator is on, or the accelerator pedal is depressed).
Judgment based only on. However, as described above, based on the information on the accelerator depression amount, it may be determined whether or not it reaches a certain reference value.

When the accelerator is depressed, the depression time counter integrates (pluses the counter value, step 411) to calculate the time counter value Ca _on . This numerical value is a time-converted numerical value and is compared with the accelerator depression time threshold Ne _on for starting the engine (step 412).

In this flowchart, the engine start
The stop routine is processed by the timer interrupt process at regular intervals, and the timer interrupt interval may be, for example, about 2 seconds. In this case, the accelerator depression time threshold Ne _on is 2 seconds. Become.

In step 412, it is determined whether or not Ca _on added in step 411 is larger than a predetermined value of Ne _on . If larger, it is determined that the accelerator depression time satisfies the condition for starting the engine. ,
In step 413, the engine start process is performed, and the control ends.

If Ca _on is smaller than the predetermined value of Ne _on , it is determined that the accelerator depression time does not satisfy the condition for starting the engine, and the control ends without starting the engine. . At this time, the depression time accumulation counter is not reset, so that the same operation is repeated again when the accelerator is further depressed, and when the accumulated time exceeds the threshold value, the engine starting operation is performed.

Even when the accelerator is continuously depressed, when the continuous depression time is less than the time threshold, that is, when the accelerator is depressed for less than the time threshold, the engine is similarly operated. The control operation ends without being started. Also in this case, step 41
A zero resets the integration counter.

As described above, in the second embodiment of the present invention,
By setting the accelerator depression time as the engine start condition, the electric motor drive is maintained without starting the engine when large driving force is not required, such as when the accelerator is depressed for a short time. ing. For this reason, useless starting operation of the engine is reduced, and occurrence of problems due to frequent starting is suppressed.

Next, a third embodiment of the present invention will be described with reference to FIG. Similar to the first embodiment described above, the present invention is applied to a hybrid vehicle and can be applied to other hybrid vehicles.

In the third embodiment, the engine stop control means uses the brake depression information, the vehicle speed information, and the remaining power information of the battery for driving the electric motor as the judgment material. The engine start control means also uses accelerator depression information, vehicle speed information, and remaining power information of the battery that drives the electric motor as the determination conditions. Further, there are provided a brake depression state detecting means, an accelerator depression state detecting means, a vehicle speed detecting means, and a battery residual power detecting means as shown in FIG. 1, each of which is a brake depression information signal and an accelerator depressing signal. The information signal, the vehicle speed information signal, and the battery remaining power signal are input to the control means.

FIG. 5 is a flow chart showing the control operation in the third embodiment of the present invention, but in the point that the remaining power information of the battery is used as the judgment condition in the engine stop and start control, the above-mentioned embodiment is carried out. It is different from, but the other points are almost the same.

The control operation of the engine stop control means in the third embodiment will be described. First, brake depression information is input (step 501).
Then, it is determined whether or not the engine is in operation (step 50
2) If the vehicle is not in operation, the routine proceeds to step 506, where the brake is normally depressed while the accelerator is not depressed, so the control operation is terminated (step 5).
07)

If the engine is in operation in step 502, the process proceeds to step 503, and the vehicle speed at this time, the remaining power information of the battery, and the depression amount of the brake depression information are fetched and described later. According to the control map shown in FIG. 6, it is determined whether the engine should be stopped.

If the engine stop condition is not satisfied, the control operation is terminated without stopping the engine (step 504). On the contrary, when the engine stop condition is satisfied, the engine stop processing operation is performed (step 505) and the control operation is ended.

By the way, in this embodiment, the determination is made in consideration of the remaining power condition of the battery in the engine stop condition. Specifically, different control maps are prepared according to the remaining power amount (SOC) of the battery in step 503, and the reference value for determination is different for each. It should be noted that these conditions may be appropriately determined according to the characteristics of the hybrid vehicle used, the capacity of the battery, the amount of driving power of the electric motor, and the like.

An example of the control map according to the SOC of the battery used in this embodiment is shown in FIGS. 6 (a) and 6 (b).
It is shown in (c). In each case, the vertical axis shows the brake depression amount (%), and the horizontal axis shows the vehicle speed (km / h). Each has a small remaining power amount (SOC ≦ 60
%), Medium (60% <SOC <80%), and sufficient (SOC ≧ 80%).

FIG. 6A is a control map when the remaining power SOC is 60% or less. In this case, it is 45 km / h set the speed threshold V _off1 a 5Km / h, and the V _off2 a to stop the engine. In addition, the threshold value β of the amount of brake depression to stop the engine
_off1 a is set to 12%. The threshold value V _on a depression amount of a brake for the threshold V _on a speed 5 Km / h, also the engine start to start the engine in the engine start control means is set to 2%.

Therefore, in step 503, when the remaining electric power amount SOC is 60% or less, it is determined whether the engine is stopped or started according to the conditions shown in this map. That is, when the vehicle speed at the time of determination is less than 5 km / h, the engine is stopped based on the fact that the brake has been depressed (information on depression is input) regardless of the amount of depression of the brake. Let

When the vehicle speed at the time of judgment is 5 km / h or more,
In the case of less than 45 km / h, the engine is stopped when the brake depression amount β exceeds 12%.
If it is less than%, the engine is not stopped. On the other hand, when the vehicle speed at the time of determination exceeds 45 km / h, the engine is not stopped regardless of the amount of brake depression.

Regarding the engine starting condition, when the threshold value of the vehicle speed exceeds 8 km / h and the brake depression amount is less than 2% of the threshold value β _on , the engine is started.

FIG. 6 (b) is a control map when the remaining electric power amount SOC is more than 60% and less than 80%. In this case, the speed threshold value V _off1 b for stopping the engine is set to 1
0Km / h, as well as the V _off2 b is set to 45Km / h. Further, the threshold value β _off1 b of the brake depression amount for stopping the engine is set to 10%. The threshold value V _on b of the vehicle speed for starting the engine in the engine start control means is set to 15 km / h, and the threshold value β _on b of the depression amount of the brake for starting the engine is set to 2%.

Therefore, in step 503, when the remaining electric power amount SOC exceeds 60% and less than 80%, it is determined whether the engine is stopped or started according to the conditions shown in this map. That is, when the vehicle speed at the time of determination is less than 10 km / h, regardless of the amount of brake depression,
The engine is stopped based on the presence of depression (information on depression is input). When the vehicle speed at the time of determination is 10 km / h or more and 45 km / h or less, the engine is stopped when the brake depression amount β _off exceeds 12%, but when it is 12% or less, the engine is stopped. Do not stop. On the other hand, the vehicle speed at the time of judgment is 45 km /
If h is exceeded, the engine is not stopped regardless of the amount of brake depression.

Regarding the engine starting condition, when the threshold value of the vehicle speed exceeds 10 Km / h and the brake depression amount is less than 2% of the threshold value β _on , the engine is started based on the accelerator depression information. It will be.

FIG. 6C is a control map when the remaining power amount SOC is 80% or more. In this case, the speed threshold value V _off1 c for stopping the engine is 15 km / h,
In addition, V _off2 c is set to 45 km / h. Also,
The threshold value β _off1 c of the brake depression amount for stopping the engine is set to 8%. The threshold value V _on c of the vehicle speed for starting the engine in the engine start control means is set to 20 Km / h, and the threshold value β _on c of the depression amount of the brake for starting the engine is set to 2%.

Therefore, in step 503, when the remaining power amount SOC is 80% or more, it is determined whether the engine is stopped or started according to the conditions shown in this map. That is, when the vehicle speed at the time of judgment is less than 15 km / h,
Regardless of the amount of brake depression, the engine is stopped based on the presence of depression (information on depression is input). Also, the vehicle speed at the time of judgment is 15K.
In the case of m / h or more and 45 km / h or less, the engine is stopped when the brake depression amount exceeds 8%, but the engine is not stopped in the case of 8% or less. On the other hand, when the vehicle speed at the time of determination exceeds 45 Km / h, the engine is not stopped regardless of the brake depression amount.

Regarding the engine starting condition, when the threshold value of the vehicle speed exceeds 20 km / h and the brake depression amount is less than 2% of the threshold value β _on , the engine is started based on the accelerator depression information. It will be started.

Here, V _off2 a, V _off2 b and V _off2
c is a value determined from the maximum rating of the generator and is set to 45 km / h in each case. Also, V _off1 a is 5 km /
h, V _off1 b is 10 km / h, V _off1 c is 15 km / h
Then, the smaller the remaining power SOC is, the smaller the speed threshold value for stopping the engine is to prevent the engine from stopping as much as possible. In addition, β _off1 a is 12%, β
_{For the same reason, off1} b is set to 10% and β _off1 c is set to 8%.

On the other hand, V _on a is 8 km / h and V _on b is 15
Km / h, V _on c is 20 Km / h, and the speed threshold for starting the engine is changed according to the remaining SOC. The reason is that when the SOC is low, the engine is started earlier.
This is because the engine was started later when there are many. Further, β _on a, β _on b, and β _on c are values determined from the rating of the generator, and all are set to 2%.

As described above, in the third embodiment of the present invention, the condition of the remaining power amount of the battery is added to the engine stop condition, and when the remaining power amount of the battery is small, stable driving of the electric motor is performed. Or, in order to maintain the auxiliary drive of the engine, the engine is not stopped as much as possible. That is, the speed threshold value _{Voff, which} is determined only by the speed, is set smaller (lower speed) as the remaining power amount of the battery is smaller.

When the power consumption further increases and the remaining power of the battery becomes about 40% or less, the engine is not stopped even when the vehicle is stopped. This is because when the engine is operated when the vehicle is stopped and power is generated, the engine speed becomes about 1500 rpm, which causes operation in a high load region and causes vibration, but if the depth of discharge of the battery becomes large. Since it causes deterioration and there is concern about the stable operation and driving force of the electric motor, in order to avoid such a situation, power is generated without stopping the engine even when the vehicle is stopped. .

Further, in the speed range in which the brake depression amount is taken into consideration, the brake depression amount to stop the engine is taken into consideration, but when the remaining battery power is small,
The engine is not stopped as much as possible in order to maintain stable driving of the electric motor or auxiliary driving of the engine. That is, the brake depression amount threshold β _off is set to be larger as the remaining power amount of the battery is smaller (low speed at which the brake is strongly depressed).

When the power consumption further increases and the remaining power amount of the battery becomes about 40 or less, the engine is not stopped no matter how large the brake depression amount is. After all, when the depth of discharge of the battery becomes large, it causes a malfunction such as deterioration, so that the engine generates electric power.

Next, the operation of the engine start control means in this embodiment will be described. When the accelerator depression information is input to the control means (step 501), it is determined whether or not the engine is in operation (step 502). If the engine is in operation, after proceeding to step 503, the normal operation is performed. Brakes are not depressed at the same time, so
The control operation is ended without stopping the engine while maintaining the operating condition.

If the engine is stopped at step 502, the routine proceeds to step 506, where the engine is started based on the remaining power information of the battery in addition to the brake depression information and the vehicle speed information according to each map of FIG. Judge whether it is good or not.

As described above, when the brake depression amount is 2% or more, and the vehicle speed is the speed threshold V for starting.
If it is less than _on , it is determined that the engine should not be started, and the control operation is terminated without starting the engine (step 507).

As described above, since the speed threshold value V _on is different depending _on the remaining power of the battery, step 5
If the engine is not started at 07, the vehicle speed is less than 8 km / h (SOC ≦ 60%), less than 15 km / h (60% <SOC <80%), 20 km / h (SOC
≧ 80%).

The reason why the speed threshold for starting is large (the speed is high) according to the remaining amount of power of the battery is that the driving force of the electric motor is sufficient. This is to suppress the generation of exhaust gas. Further, it is to prevent unnecessary fuel consumption and the occurrence of problems associated with the starting operation by reducing the number of times of starting the engine without performing the starting operation of the engine as much as possible.

When it is judged in step 507 that the engine should be started (when the speed is at least the speed threshold value V _on , according to the control map according to the battery remaining amount in FIG. 6), it is necessary. In accordance with the above, the remaining battery power information as an engine starting condition is added (step 5).
08).

At step 508, the battery residual amount threshold value S _on for starting the engine is set to 70%,
When the remaining battery charge SOC is less than 70%, the routine proceeds to step 510, where the engine start processing operation is performed as it is.
When the battery state of charge SOC exceeds 70%, the routine proceeds to step 509, where accelerator depression information is determined.

In step 509, similarly to the above-described embodiment, the determination is made based only on the state in which the accelerator is depressed (the accelerator is on or the accelerator pedal is depressed).

However, as described above, the judgment condition may be whether or not it has reached a certain reference value based on the information on the accelerator depression amount. As this reference value,
Considering the input error of the sensor, the amount of play, etc., for example, about 2% can be adopted.

The engine start control means does not have to use the same control map as the engine stop control means.
For example, the starting control means may always follow the control map of FIG. 6C, and may be configured to start the engine only when the remaining power amount of the battery is less than 70%.

For example, also in this embodiment, if the information signal when the accelerator depression information is 0 (zero) is also taken in, the speed is 8 km / h or more regardless of whether the accelerator is actually depressed. In this state, if the brake is not depressed (the depression amount is less than 2%), the control for starting the engine is performed.

That is, in the third embodiment, when the brake information is detected while the engine is stopped, it is based only on the battery remaining power amount information (not on the accelerator information).
May start the engine. In other words, the engine start control means controls the engine start based on the remaining battery power information and the vehicle speed information.

More specifically, when the brake information is input and the engine is stopped, step 506 is performed.
The conditions for determining whether or not to start the engine are defined according to the control map according to the remaining battery level. At this time,
If the vehicle speed exceeds the speed threshold V _on for starting the engine and the brake depression amount is less than the depression threshold β _on for starting, it is determined in step 507 that the engine should be started. In step 508, the remaining power amount of the battery is determined. When the remaining power amount of the battery is 70% or less which is the battery remaining amount threshold value S _on , the engine start processing operation is performed.

As described above, in this embodiment, the condition for starting the engine is satisfied without the accelerator depression information, and the engine is started. This is for protecting the operation of the electric motor, and is an engine start control operation for always accumulating a sufficient amount of electric power in the battery to drive the electric motor. For this reason, the engine started here is mainly used for driving the generator.

[0215]

As described above, according to the present invention,
It is possible to smoothly drive the hybrid vehicle, reduce energy loss, and reduce cost.

That is, according to the present invention, the engine is stopped when it is not necessary to operate, and the engine is operated only when it is necessary. Therefore, it is possible to suppress fuel consumption by stopping the engine and to start the engine. Fuel loss due to frequent occurrence prevention can be suppressed at the same time.

Further, according to the present invention, by appropriately selecting the engine stop condition, the engine is not stopped in an unfavorable state, and the number of start operations is reduced. It is possible to suppress the occurrence of noise, noise, cranking, and unnecessary fuel consumption and harmful exhaust gas.

On the other hand, according to the present invention, by properly selecting the engine starting condition, the engine is not started under the condition where the operation is not preferable, so that the number of times of the starting operation is reduced, and the vibration and noise accompanying the starting operation are reduced. Occurrence of
It is possible to suppress wasteful fuel consumption and generation of harmful exhaust gas.

Furthermore, by reducing the starting operation of the engine, the load on the starter motor can be reduced, the durability of the starter mounted can be reduced, and the weight and manufacturing cost of the hybrid vehicle can be reduced. it can.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing a schematic configuration of a control means of a hybrid vehicle according to an embodiment of the present invention.

FIG. 2 is a flowchart showing control states of an engine stop operation and an engine start operation according to the first embodiment of the present invention.

FIG. 3 is a control map showing an engine stop condition and an engine start condition according to the first embodiment of the present invention, in which the vertical axis represents the brake depression amount (%) and the horizontal axis represents the required speed (Km / h). ).

FIG. 4 is a flowchart showing a control state of an engine stop operation and an engine start operation according to the second embodiment of the present invention.

FIG. 5 is a flowchart showing control states of an engine stop operation and an engine start operation in a third embodiment according to the present invention.

FIG. 6 is a control map showing an engine stop condition and an engine start condition in a third embodiment according to the present invention, in which a vertical axis represents a brake depression amount (%) and a horizontal axis represents a predetermined speed (Km / h). ).

FIG. 7 is a conceptual diagram showing a schematic configuration of a general hybrid vehicle, in which (A) is a series type, (B) is a parallel type, and (C) is a parallel type modification type.

FIG. 8 is a graph showing the relationship between the brake depression amount and the regenerative torque, in which the vertical axis represents the regenerative torque and the horizontal axis represents the vehicle speed.

FIG. 9 is a graph showing the relationship between vehicle speed and engine speed, in which the vertical axis represents engine speed (rpm) and the horizontal axis represents vehicle speed (Km / h).

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location F02D 29/02 321 B60K 9/00 Z H02J 7/00

Claims (7)

[Claims] 1. A hybrid vehicle including an engine and an electric motor, capable of stopping the engine while the vehicle is running, wherein the engine is based on the amount of depression and / or the depression time of an accelerator of the vehicle when the engine is stopped. A hybrid vehicle comprising an engine start control means for starting the engine. 2. The hybrid according to claim 1, wherein the engine start control means starts the engine only when the speed of the hybrid vehicle is higher than a predetermined start speed threshold value. Type vehicle. 3. The engine start control means starts the engine only when the remaining power amount of the power storage means for driving the electric motor is less than a predetermined starting power threshold value. The hybrid vehicle according to claim 1. 4. A hybrid vehicle including an engine and an electric motor, capable of stopping the engine while the vehicle is running, wherein the engine is based on the amount of depression and / or the depression time of the brake of the vehicle when the engine is operating. A hybrid vehicle comprising an engine stop control means for stopping the engine. 5. The hybrid system according to claim 4, wherein the engine stop control means stops the engine only when the speed of the hybrid vehicle is smaller than a predetermined stop speed threshold value. Type vehicle. 6. The engine stop control means stops the engine only when a remaining power amount of a power storage means for driving the electric motor is larger than a predetermined stop power threshold value. The hybrid vehicle according to claim 4. 7. A hybrid type vehicle comprising an engine as a vehicle drive source and an electric motor, wherein the engine can be stopped while the vehicle is running, and a brake detecting means for detecting a stepping amount of a brake of the vehicle, and a vehicle. Accelerator detection means for detecting the accelerator pedal depression state, engine detection means for detecting whether or not the engine is operating, vehicle speed detection means for detecting the speed of the vehicle, and electricity storage for driving the electric motor. A power storage detection unit that detects the remaining power amount of the storage unit, and based on the remaining power amount of the power storage unit detected by the power storage detection unit when the engine detection unit detects that the engine is stopped. The determined starting speed threshold value and the brake depression amount starting condition, and the vehicle speed and the brake detected by the vehicle speed detecting means. Compare the amount of brake depression detected by the rake detection means,
Engine start determining means for determining whether to start the engine; engine starting means for starting the engine when the engine start determining means determines that the engine should be started; and the engine detecting means. When it is detected that the engine is operating, the stop speed threshold and the brake depression amount stop condition determined based on the remaining power amount of the power storage unit detected by the power storage detection unit, and the vehicle speed detection unit. An engine stop determination unit that determines whether to stop the engine by comparing the detected vehicle speed and the amount of brake depression detected by the brake detection unit, and stops the engine by the engine stop determination unit. And an engine stopping means for stopping the engine when it is determined that the engine should be operated. And hybrid vehicle, wherein are.